Have you ever known someone who never seems to gets sick? One of those lucky souls who’s just flat-out bulletproof even when flu fells her family or rages through her workplace? Truth is, it’s not just luck—or even vigilant hand washing—that’s keeping these people virus-free. Evidence is growing that the secret to staying well during cold and flu season is due in large part to the food on our plates, in the same way that a healthy diet can prevent diabetes, osteoporosis and cardiovascular disease, and is increasingly thought to play a role in battling other illnesses such as Alzheimer’s and cancer.

The immune system is your body’s natural defense against infections; its role is to keep your body healthy and stop pathogenic invasions. About 70% of your immune system lines the intestines of your digestive system, as that is where most pathogenic microorganisms first contact your body. Your immune system is made of many different kinds of bacteria, such as Lactobacillus casei, called the intestinal microflora.

When a pathogen first tries it infect you, your immune system will take a defensive stand: it puts into play a physical barrier to protect itself from the potential plague, this answer is called innate immunity. If this defense is not affective, a second line of defense will come in play, 96 hours later. This second line of defense is stronger than the first, as your immune system has now recognized the type of pathogen trying to invade; and it has formed a memory of its characteristics. Your immune system will therefore act more quickly and will target the weaknesses of this pathogen.

How can probiotics help strengthen your immune system?

Probiotics are another term for the beneficial bacteria found in your gut that fights infections. For probiotics, the expression “the more the merrier” definitely applies. The more probiotics are in your intestines, the more efficient your immune system will be. Probiotics come in the form of many different strains of bacteria, so as to better target and fight pathogens.

During periods of cold, fatigue or high stress, your probiotics count can sometimes be down, making your body more vulnerable to potential invasions. The solution to this problem however is simple: add probiotics to your diet. Probiotics will line your intestines and work hand in hand with your already existing defenses to strengthen your immune system, efficiently combat illness, and improve your general health and wellbeing.

Probiotics is a big buzzword these days—with good reason. Those “active live cultures” found in yogurt and fermented foods are healthy bacteria that work to balance the 100 trillion microbes that live in the GI tract. Our “second brain,” as the gut has been called, is known to control everything from our mood to how many calories are absorbed from food. What’s more, “we’ve also learned that our immune system is headquartered in our gut,” says Alpert. “I’ve watched many clients start taking a probiotic and then see a major decrease in the amount of colds they’ve caught, not to mention loads of other health benefits.

Article originally appeared on La Playa Pilates (http://laplayapilates.com/).